The present invention relates to a penstocker used for an automatic drafting machine in which the penstocker and a line drawing head can automatically and mutually exchange writing instruments such as pens.
In one example of an automatic drafting machine provided with a rotary penstocker, a plurality of slits 3 have been provided on the peripheral wall 2 of a rotary penstocker main body 1 having a plurality of pen holding portions 1a, as shown in FIG. 6. A light transmitting type object detecting sensor 5 is used to detect these slits 3. A controller discriminates the presence or absence of the penstocker, the type of pen held by the penstocker and an origin of the penstocker based on the detecting signals.
In this apparatus, the slits 3 are provided on the peripheral wall 2 of the penstocker main body 1. A slit arrangement pattern is changed by sticking an adhesive tape such as shield member 4, on the face of a desired slit or slits.
If a water ball pen, an ink pen or a ceramic pen have the same configuration, a penstocker having a pen holding portion for the water ball pen can also hold the ink pen or the ceramic pen. However, where the ink pen or the ceramic pen is held by this penstocker when the slit pattern of the penstocker is set for the water ball pen, it is necessary to apply adhesive tape to different slits so that the predetermined slit arrangement of the penstocker is modified to represent the ink pen or the ceramic pen. Thus, where the kind of pen to be held in the penstocker is predetermined, only that kind of pen may be accommodated unless the slit pattern is modified as, for example, by applying adhesive tape to the slits.
Thus, if it is desired to use many different kinds of pens in a single penstocker without exchanging pieces of adhesive tape on the slits, it is necessary to change the stocker data of a controller each time a different pen is to be used.
An object of the present invention is to solve the above-mentioned problems.